Tunnel kiln



March 2 1926. 1,575,470

H. w WEBER ET AL.

TUNNEL K ILN Filed Nov: 27, 1925 3 Sheets-Sheet 1 l/Qvszv T0785 flex-man 71 Weber.

March '2 1926. 1,575,470

H. w. WEBER ET AL TUNNEL KILN Filed NQV. 27, 1925 3 Sheets-Sheet 2 B-VMNQQW QTTOFPNE VS jA/VENTOEI? March 2 1926. 1,575,470

H. W. WEBER ETAL.

TUNNEL KILN Filed Nov. 27, 1925 3 Sheets-Sheet 5 Patented Mar. 2, 1926.

UNITED STATES 1,575,470 PATENT OFFICE.

HERMAN w. WEBER, or MAPLEWOOD, AND ARMIN o. SGHLEIFFARTH, F s1. LOUIS, 'mrssouar, ASSIGNORS T0 RUSSELL ENGINEERING COMPANY, OF s1. LOUIS, ms.

SOURI, A CORPORATION OF MISSOURI.

TUNNEL KILN Application filed November 27, 1925. Serial No. 71,688.

To all whom. it may canoe-rm.

Be it known that we, HERMAN W. WEBER and ARMIIN O. SCHLEIFFAR'IH, citizens of the United States,'residing in Maplewood, Mis- 6 so'uri, and the city of St. Louis, State of Missouri, respectively, have invented a certain new and useful Improvement in Tunnel Kilns, of which the following is a full, clear,

and exact description, such as 'will enable 10 others skilled in the art to which it appertains to make and use the same.

This invention relates to kilns that are used for. burning clay products, and particularly tunnel kilns of the type that comprise a preheating zone, a firing zone anda cooling zone arranged so that cars containing the ware or clay products can be moved slowly through the preheating zone, then through the firing zone and then through the cooling.

zone;

One object of our invention is to provide a tunnel kiln of the type referred to which s I proy ided with meansfor causing the hot air and products of combustion to circulate through the discharge end portion of the preheating zone insuch a manner that the temperature of said discharge end portion is maintained substantially uniform throughout its entire height.

Another object is to provide a tunnel kiln in which the cooling zone is constructed in a novelmanner that insures rapid radiation of the heat from the ware in said cooling zone.

And still another ob'ect of our invention is to provide a tunnel iln that is equipped with an efiicient means of simple design for supplying preheated air to the burners of the firing zone.

Figure 1 of the drawin s is a side elevational view of a tunnel kiln constructed in accordance with our invention.

Figure 2 is a transverse sectional view, taken on the line 2--2' of Figure 1.

Figure 3 is a vertical longitudinal sectional view, taken on the line 3=- -.3 of Figure 2.

Figure 4 is a transverse sectional View through the cooling zone, taken on the line 50 4-4 of Figure 1.

Figure 5 is a longitudinal sectional view, taken on the line 55 of Figure 4.

Figure 6 is a transverse sectional view,

' taken on the line 6-6 of Figure 1.

Figure 7 is a vertical longitudinal sec-' tional View, taken on the line 7--7 of Figure 6.

Figure 8 is averti'cal transverse sectional vieav, taken on the line 8-8 of Figure 1; an

Figure 9 is a vertical longitudinal sectional view, taken on the line 9-9 of Figure 8.

Referring to the drawings, which illus trate the preferred form of our invention, the reference character A in Figure 1 designates the preheating zone of our improved kiln, B designates the firing zone,and G designates the cooling zone. The kiln is provided with track rails 1 on which cars 2 containmg the Ware :1: travel longitudinally of 'thekiln" first throu h the preheating zone,

firing zone and then then through the through the cooling zone. The preheating zone A is provided in its side walls adjacent the lower portion of said zone with outlet ports 3, as shown in Figure 6, through which the air and products of combustion can escape from said zone into longitudim.

ally-disposed flues D that extend longitudmally of the preheating zone to a stack,

fan or other suitable draft-creating means E which is located some distance from the receivlng end of the preheating zone, as shown in Figure 1, said flues D being provided in their top Walls With ports 3 located adjacent the outlet ports 3 leading from the preheating zone so as to permit the air and products of combustion which escape from the preheating zone to enter the flues D and flow longitudinally of same, finally escaping through the stack or draft creating means E that is used to induce circulation longitudinally of the flues D. Said outlet orts 3 and the ports 3 in the top wall 0 I the flues D are arranged in spaced relation throughout that portion of the ,preheating zone which lies between the firing zone B and the suction-producing means E, and dampers or other suitable devices 4 are provided for controlling the escape of the air and products of combustion from the preheatin zone into the flues D, and thus .regulate t e temperature in this portion of the preheating zone. In the form of our invention herein illustrated the dampers or valves 4 are formed by members constructed of refractory material that can be slidinto and out of alignment with the ports 3 in the top walls of the longitudinally-disposed flues D, the outer portions of the side walls of the preheating zone having openings in alignment with the outlet ports 3 through which devices can be inserted to engage the dampers 4 and move them into and out of registrati n with the ports 3 in the top walls of t e flues D. Normally, these openings in the outer portions of the side walls of the preheating zone are closed by doors or removable closures designated by the refence character 5 in Figure 6.

In order to produce a substantially uniform temperature in the discharge end portion of the preheating zone A, means are provided for causing the air and products of combustion in this portion of the reheating zone to circulate vertically through same either upwardly or downwardly. Various means may be used to attain this circulation of the air and products of combustion in the discharge end portion of the preheating zone, but in most instances said means will consist of fans F arranged so as to withdraw the relatively hot air and products of combustion from the top of the preheating zone and force said hot air and products of combustion into the bottom portion of the preheating zone, thereby main taining the discharge end portion of the preheating zone at a substantially uniform temperature throughout its entire height. If desired, the fans F can be arranged so as to withdraw the cooler air and products of combustion from the lower portion of the preheating zone and discharge said air and products of combustion into the to portion of the preheating zone. We pre er, however, to equip the discharge end portion of the preheating zone with one or more transversely-disposed flues 6 arranged above the arch or top wall of the preheating zone, as shown in Figure 2, and each associated with a fan F that causes hot air or products of combustion to be withdrawn from. the preheating zone into the flue 6 through a port or ports 7 in the top wall of the preheating zone and then discharged downwardly through a vertical flue 8 in the side wall of the preheating zone, which is provided at its lower end with a discharge port 9 through which said hot air or products of combustion is returned to the preheating zone. The blades of the fan F are formed from a metal that is capable of successfully withstanding extremely high temperatures, and the casing of said fan is formed of refractory ma-.

terial, the eye or inlet opening 10 of the fan casing being arranged at one end of the transversely-disposed to flue. 6 with which said fan co-operates. ny suitable means can be used for driving the fans F,'the means herein illustrated for this purpose consisting of an electric motor G for each fan arranged be withdrawn from said firing zone and Gil culated longitudinally through the preheating zone by the stack or draft-creating means E, and while said hot air and products of combustion are traveling through the discharge end portion of the preheating zone, said hot air and products of combustion are kept in a state of agitation or caused to circulate vertically by the fans F which withdraw the hot air through the discharge ports 7 in the top wall of the preheating zone and return said hot air to the bottom portion of the preheating zone through the inlet ports 9 at the lower ends of the vertical flues 8 which lead from the discharge ends of the fan casings.

As previously stated, the cooling zone C is constructed so that the heat will radiate rapidly from the ware traveling through .said zone. This highly desirable result is attained by arranging an air flue H above the major portion of the top wall 11 of the preheating zone C, as shown in Figures 4: and 5, and providing said top wall with metallic members 12 which rapidly absorb heat thrown off from the cooling ware and radiate said heat into the flue H. One con-' venient way of building the top wall 11 of the cooling zone is to construct it from re-' fractory material in the form of an arch and provide it with openings over which metal plates 12 are arranged, said metal plates being supported by the refractory arch and retamed position by integral, downwardlyprO ectmg flanges 12 on said plates that project into the openings in the arch, as shown clearly in Figures 4 and The particular design of the top wall of the cooling zone C is immaterial, however, so far as our broad idea is concerned, so long as said top wall 15 equipped with a means that tends to cause the heat to radiate rapidly from the cooling zone G into the air flue H above said zone, Any suitable means can be used for causing air to circulate longitudinally through the flue H, so as to carry away the heat conducted into said flue by the radiatlng devices 12, the means herein illustrated for this purpose consisting of a blower or fan 13 arranged at one end of the flue H in such a manner that it forces a relatively large volume of air through the flue H towards an eduction pipe 14. Theair, in traveling through the flue H, becomes highly heated. Consequently, if the eduction pipe 14 is connected with a device that consumes hot air or which is operated by hot air, no expense is attached to the operating of said device.

Another feature of our invention which we believe to be novel is utilizing the hot the cooling zone C, i. e., that portion of the cooling zone which is located in close proximity to the firing zone B, said top wall 11 having numerous ports or openings 16 in same' through which the hot air in said zone rises and comes in contact with the air heating devices 15. The devices 15 preferably consist of a group of tubes whose opposite ends are connected to headers 15 and 15", the header 15 being connected by a supply pipe 17 to a fan or blower "18 that is used for forcing air longitudinally through the pipes 15, and the header 15 being connected to a manifold 19 from which branch pipes 20lead to the burners 21 of the firing zone. The air that is forced through the pipes 15 becomes highly heated by the heat which said pipes absorb from the hot air that rises through the ports 16 in the top wall of the receiving end portion of the cooling zone C, and consequently, the burners of the firing zone will be supplied with preheated air under pressure.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

1. A tunnel kiln provided with a pre heating zone, a flue arran ed transversely across the top wall of sai zone and provided with an inlet through which hot air and products of combustion can pass from said zone into said flue, a fan at one end of said flue for inducing a circulation l0ngitudinally of same, and a vertical flue at the side wall of the preheating zone connected with the discharge of said fan and, provided with a port through which the hot air and products of combustion are returned to the lower portion of the preheating zone.

2. A tunnel kiln provided with a preheating zone, a flu'e arranged transversely across the top wall of said preheating zone, a port in said top wall that establishes communication between said zone and flue, a vertical flue in the side wall of the preheating zone provided at its lower end with a discharge port that leads to the lower ortion of said preheating zone, a fan w ose casing has its intake connected with one end of said transversely-disposed flue and its discharge connected with said vertical flue, and means arranged onthe exterior of said casing for driving the blades of said fan so as to cause hot air and-products of combustion to be withdrawn from the top portion of the preheating zone and returned zone, an air flue arranged longitudinally of said zone above the top wall of same, means for causing air to, circulate through said flue, and metallic heat radiating devices arranged in the top wall of said zone for absorbing heat from the cooling ware and transmitting said heat to the air flowing through said flue.

l. A tunnel kiln provided with a cooling ing zone having a top wall constructed from refractory material and metallic heat 1'adiating devices, and means for causing air to circulate over said heat regulating devices and carry away the heat which said devices absorb from the cooling ware.

5. A tunnel kiln provided with a cooling zone, an air flue arranged longitudinally over the top wall of said zone, a blower at one end of said flue for forcing air longitudinally through the same, and metallic heat radiatin devices in the top wall of said zone for radiating the heat thrown oil by the cooling ware.

(i. A'cooling zone for tunnel kilns provided with a top wall constructed in the form of a refractory arch having openings in same, metallic heat radiating devices supported by said arch and arranged over said openings, and means for causing air to circulate over said heat radiating devices and carry'away the heat which said devices absorb from the ware in the cooling zone.

7 A tunnel kiln, comprising a firing zone provided with burners, a cooling zone, tub-ular metallic air heating devices arranged over openings in a portion of the top wall of said cooling zone, headers to which the opposite ends of said devices are connected, a blower or fan-connected with one of said headers for forcing-air into same, and a 8. A tunnel kiln, comprising a preheating zone, a firing zone, a cooling zone, a suction device arranged intermediate the ends of the preheating zone 'for inducing a circulzn tion longitudinally of said zone towards the receiving end of same, means for producing a vertical circulation in a portion of the preheating zone lying between said suction device and said firing zone, an air flue arranged longitudinally over a portion of the top wall of the cooling zone, means for forcing air longitudinally through said air flue, and metallic heat radiating devices in the top wall ofthe cooling zone for radiating the 7 heat thrown ofl from the cooling ware. to the air flowing through said air flue. I

9. A tunnel kiln, comprising a preheating zone, afiring zone, a cooling zone, a suction device arrangedintermediate the ends of the preheating zone for inducing a circulation longitudinally of said zone towards the receiving end of same, means for producing a vertical circulation in a portion of the preheating zone lying between said suction device and said firing zone, an air flue arranged longitudinally over a portion of the top wall of the cooling zone, means for forcing air longitudinally through said air flue, nietallic heat radiating devices in the top wall of the cooling zone for radiating the heat a cooling zone, a'suction device located intermediate the ends of the preheating zone,

longitudinally disposed flues in the portion of the preheating zone lying between said suction device andsaid firing zone, ports through which the air and products of combustion can pass from said preheating zone into said fines, adjustable valves or dampers for regulating said ports, fans located between the suction device and the firing zone for withdrawing the hot air and products of combustion from the top portion of the preheating zone and returning said air and products of combustion to the lower portion of, the preheating zone, metallic heat radiating devices embedded in the top wall of the cooling zone, and means for causing air to circulate over said heat radiating devices and carry away the heat which said devices absorb from the ware inthe cooling zone.

11. A tunnel kiln, comprising a preheating zone, a firing zone equipped with burners, a cooling zone, a suction device located'intermediatethe ends of the preheating zone, longitudinally-disposed fines in the portion of the preheating zone lying between said suction device and said firing zone, ports through which the air and products of combustion can pass from said preheating zone into said flues, adjustable valves or dampers for regulating-said ports, fans located between the suction device and the firing zone for withdrawin the hot air and products of combustion rom the top portion of the preheating zone and returning said air and products of combustion to the lower portion of thepre-heating zone, metallic heat radiating devices imbedded in the top wall of the cooling zone, means for causing air to circu- Ilate over said heat radiating devices and any away the heat which said devices absorb from the ware in the cooling zone, hollow metal air heating devices arranged so as to be heated by the heat thrown off from the ware in the cooling zone, and means for causing air to flow thronghsaid air heating devices and then pass to the burners of the firing chamber.

HERMAN W. WEBER. ARMIN O. SCHLEIFFARTH. 

